Never limit your prayer just because you think you're sinful or undeserving. You're not praying because of who you are - you're praying because of who He is!
The HIV, HPV, AIDS, Herpes, & Chlamydia rate is way too damn high to be having hoes, side pieces, and unprotected sex with random people just cause you're "horny". Sex requires TRUST. You're trusting another individual with your body, and essentially your life.